Linux virtual desktop: “Remote” audio-video access

“The post documents how I set up my Linux desktop system. My particular system runs inside VirtualBox on Windows, but most of the discussion here applies to any Linux productivity desktop.
You may wonder why I am running on VirtualBox. There are a few reasons:

1. With VirtualBox, I can run a Windows system and a Linux system on the same piece hardware at the same time.
2. Windows has much better hardware driver support than Linux, especially around power management.
3. VirtualBox provides virtual hardware to the Guest Linux OS, and this hardware is much better supported by Linux than real hardware.

Headless Linux

Linux has a client-server architecure that allows us to run a program on one machine that sends its output to another machine. “Output” includes text, and also graphics and sound!

When we run a program without using the video/audio/text console of the machine where the program is running, we say the program is running “headless”. To make use of such a program, we run a video/audio/text server on a different machine (usually the one where we are sitting, which is not where the program is running).

This section explains how to run Audio and video servers on Windows, for use with programs on remote Linux systems.

Video Setup: XWin video server

You’ll need Cygwin/X to make graphics work.
Run XWin Server on your local/host machine, using the Shortcut or the command:

C:\Program-Files\Cygwin\bin\run.exe /usr/bin/bash.exe -l -c /usr/bin/startxwin.exe

Set and export DISPLAY (It’s best to due this in ~/.bashrc, so it runs automatically in every shell session):

export DISPLAY=:0

eSound audio server

We need to install a sound server on Windows, to play sounds sent back from the remote Linux system. Esound and Cygwin come to the rescue:

Run Cygwin setup.exe and choose to install “eSound”.

Then, run eSound (in a loop, in case it dies):

while true ; do esd.exe -tcp -public ; sleep 5; done

You’ll probably want to stow this command somewhere that will make it run exactly once each time you boot your Windows machine.

Connecting your Headless system

Use ssh to connect to the Linux machine.

• Add the –Y option to enable X forwarding, so you can see the GUI of guest OS programs on your local desktop.
• Add the –R option to set up a tunnel for eSound

ssh –Y -C -R 33001:localhost:16001 linux_user@linux_machine

When you log in to the Linux machine, instruct your session to send eSound output over the network through your tunnel.

export ESPEAKER=127.0.0.1:33001

Run your favorite programs with graphics and audio, like xterm or even firefox.  You’ll need to instruct any program you run to send its sound to eSound. Consult the documentation for each individual program.
For example:

ESPEAKER=127.0.0.1:33001 FIREFOX_DSP="esddsp" firefox

(This works using Cygwin/POSIX. You might need to tweak things to run from a Windows command shell.)
Reference: http://www.gbar.dtu.dk/wiki/Remote_Sound#1._Manually_by_SSH